Question

The magnetic field strength of a current carrying wire at a particular distance from the axis of the wire

(a) depends upon the current in the wire

(b) depends upon the radius of the wire

(c) depends upon the temperature of the surroundings

(d) None of the above

Answer 1

(a) depends upon the current in the wire

The magnetic field strength of a current carrying wire at a particular distance from the axis of the wire is given by the Biot-Savart's law.

Magnetic field, dB ∝ idl sinθ / r²

where, i = current in wire

and r = distance of the point from the wire.

dB ∝ i